According to Computerworld, Adobe has admitted that hackers are actively exploiting a bug in Reader PDF viewer and the Acrobat PDF maker. This would make the fourth time this year that hackers were using malicious PDF documents to break into Windows PCs.
Adobe's security advisory says the bug lies in Reader and Acrobat versions 9.1.3 and earlier on Windows, Mac OS and Linux. According to the advisory:
There are reports that this issue is being exploited in the wild in limited targeted attacks; the exploit targets Adobe Reader and Acrobat 9.1.3 on Windows.
Adobe plans to patch the bug on Oct. 13, the same day Microsoft plans to release the biggest Patch Tuesday ever. Adobe missed its planned Sept. 8 update because it spent most of July scrambling to fix two critical security problems.